West Yorkshire Police were called to Sandford Road in Bradford at about 1.10pm on Wednesday after a report of a collision where two pedestrians were injured.
The occupants then got out of the car and assaulted the two men, before making off from the scene.
One of the men, 40, was taken to hospital in a serious condition. He has since died as a result of his injuries.
The second man remains in hospital.
A 35-year-old man has been arrested in connection with the incident and remains in police custody.
Detectives in the Homicide and Major Enquiry Team are continuing enquiries and are investigating the incident as murder.
Anyone with information or anyone who witnessed the incident is asked to contact police on 101.